The Metropolitan police force is facing a crisis in public confidence following fresh revelations of serious mistakes that left a serial rapist free to attack scores of women.

Only weeks after acknowledging failures in the investigation of the black-cab rapist John Worboys, Scotland Yard is under a barrage of criticism for not catching and stopping Kirk Reid, a south London chef who raped and sexually assaulted more than 71 women over eight years.

He had been identified as a suspect for a series of sex attacks in 2004 and crossed the police radar at least 12 times, but no one pursued inquiries into him. He went on to attack at least 20 women.

Senior figures fear the force is facing a "Macpherson" moment over its rape and sex crime investigations, referring to the criticism that engulfed the Yard after the racist killing of the black teenager Stephen Lawrence in 1993.

As Reid was convicted at Kingston crown court yesterday of two counts of rape, three of assault by penetration and 21 indecent assaults, John Yates, assistant commissioner of the Met and the national police spokesman on rape and sexual assault, acknowledged there had been errors in the case.

"Nothing can adequately excuse the failure to follow up straightforward lines of inquiry that should have seen Reid arrested at that time [2004]," said Yates, writing in the Guardian.

Acknowledging that there were comparisons to be made with the fallout from the Lawrence case, where the Met was accused of being "institutionally racist" for failing to investigate the murder properly, he said: "We need ... to reinvent our response in the way that we did in relation to homicide after the tragic murder of Stephen Lawrence."

He said that although there were examples of good police work across the country into rape allegations, there were "too many and significant inconsistencies in the investigative response at every level", not just in London but across England and Wales. "Rape cases simply do not get the attention they deserve," he conceded.

The judge in the Reid case, who delayed sentencing yesterday for the preparation of a psychiatric report, accused the Met of "inadequately" investigating the serial attacks in south London for which Reid was responsible.

The Independent Police Complaints Commission, which is investigating the police failings, said the Reid case was "real cause for concern." IPCC commissioner Deborah Glass said: "There have been a number of cases in which the response by police to victims of sexual offences has been called into question ... there is a real need for independent scrutiny."

Reid, who was an amateur referee of women's football matches, struck in south London in the early hours, targeting women walking home alone.

He was only brought to justice when the investigation was passed last January to an experienced detective from within the homicide and serious crime command. After eight years of failings, the detective took just hours to identify Reid as a key suspect and within five days he had matched his DNA to two indecent assaults from 2001 and a rape a year later.

Detective Inspector Justin Davies was praised by the judge, Shani Barnes, for "excellent" police work. He said: "[Reid] is a devious sexual predator who has preyed on women for a number of years."

Sir Paul Stephenson, the Met commissioner, has admitted he has very real concerns about public confidence in his force ebbing after its repeated failures over years in rape and sexual assault inquiries.

An internal review of the Reid case identified a "number of concerns in the standard of investigations", and he said efforts were being made to "learn lessons" and send a message to women that the force could be trusted. But he said: "Will this instantly solve the public confidence problem? No, of course not. Clearly we are very concerned."

The details of how officers missed at least 12 chances to stop Reid come within weeks of the Worboys case. The black-cab rapist was able to continue his rapes and sexual assaults on hundreds of women in the capital for years partly because police did not believe his victims.

The IPCC, which is investigating the failings in the Reid and Worboys investigations, identified a series of failings in a rape inquiry in 2005. Four officers are to be disciplined as a result of the findings by the Met's directorate of professional standards.

The report on the case contained testimony from senior members of the specialised sex crime investigative Sapphire unit in Southwark which described a department in crisis because management - who were concerned with hitting national targets - considered car crime a higher priority than rape and sex offences.

The Met has already announced that command of the Sapphire units will be handed to the control of assistant commissioner Yates, within the experienced homicide and serious crime command.